1. Field of the Invention
The invention relates to a device for controlling the flow of fluids through PVC tubing. The device has particular application in blood salvage units used to remove blood from a patient before or during surgery and clean the blood for reinfusion into the patient.
2. Description of the Related Art
Surgical patients often require blood infusion during surgical procedures to replace lost blood volume. Due to an increased risk of contracting communicable diseases such as AIDS from blood donors, it has become more desirable in recent years to replace lost blood volume with a patient's own blood. This can be accomplished in two ways. Prior to surgery, blood can be removed from a patient and stored for later use. Alternatively, blood may be suctioned from surgical cavities during a surgical procedure, cleaned, and reinfused into a patient during the same procedure.
In both instances, the blood must be processed before reinfusion. This processing includes centrifuging the blood to separate red blood cells from waste product and plasma, and rinsing the red blood cells. This process requires an iterative rinsing and centrifuging operation in order to insure that the red blood cells are completely clean.
During this process, biological and medical fluids are typically passed through numerous tubing lines connected to a blood cell separator unit. Tubing lines have to be opened and closed at precise times in order to ensure that the blood is properly processed and that fluids do not enter the wrong lines. Such occurrences could have catastrophic effects.
Unfortunately, such procedures are usually carried out under the pressure of an emergency room and/or surgical situation, and therefore there is not only a need to enable an operator to quickly initiate the blood collection process, but also to provide a device that minimizes the risk of error.
Typical blood salvage equipment includes a series of occluders for controlling the flow of fluids through the blood salvage unit. A typical occluder includes a plunger that presses against a flexible piece of plastic tubing to block flow through the tubing. When the plunger is released, fluid flow through the tubing resumes. In the typical blood salvage unit, each plunger is associated with a separate actuator whose operation is controlled by software. In the event of a software or electrical malfunction, two valves could open at the same time, with undesirable consequences.
As with most surgical procedures, time is of the essence and the time it takes to prepare a medical device for use can be critical. Some manufacturers therefore sell preassembled packages of centrifuge bowls, plastic tubing, and plastic fluid bags to minimize both connection errors and set-up time. However, even with these preassembled packages, an operator must still independently position a number of different tubes, which takes time and increases the risk of error.